It was life imitating reality television. When a woman recently arrived at a valuation day offered by international auctioneers and valuers Bonhams in Melbourne, she clutched a dish her parents had brought to Australia from China.

It was a family heirloom, but the number of fakes made in China mean that's no guarantee of value, says John Chong, Bonhams' Hong Kong-based Chinese paintings and ceramics specialist.

"Sometimes it might not be of historical value, but it is quite important to them in terms of feelings so it is important that we take care of their feelings," Chong says. "We tell them it would not be suitable for auction, and they understand."

This time the client was in for a shock. "She did not know what she had," says Jennifer Gibson, head of furniture and decorative arts for Bonhams, Australia. "She occasionally put things in the bowl and definitely used it, God forbid."

We want to educate people and make sure they don't make rash decisions

That dish, an imperial yellow, will now be featured in Bonhams' May sale in Hong Kong, where it is expected to fetch more than HK$60,000. Also consigned for sale will be a white glazed bowl, whose owner did know it was valuable and wanted to know what price it might fetch, along with several paintings and scrolls.

For Chong and Hong Kong colleague Vincent Wu, finding such treasures is one of the joys of valuation days. Bonhams' Hong Kong specialists have visited Australia twice yearly for two years. This year, with the recent opening of the London-based auction firm's Melbourne office, the pair spent two days there and two in Sydney.

There have been bigger surprises. A traditional Chinese painting by Wang Shimin (1592-1680) titled Stream, Mountain, Rain, Feeling (Landscape in the Manner of Huang Gongwang), sourced from Down Under in 2011, sold for HK$11.9 million, 10 times its estimate.

Chong and Gibson agree that with Australia's Chinese population growing, more buyers and collectors are based there, and there is a greater chance of finding choice items.

"There are a lot of Chinese migrants ... Naturally, their families brought quite a lot of their family collections with them when they emigrated to Australia," says Chong. "The younger generations probably inherited these items from their parents or grandparents and might not enjoy them as much and think maybe it's a good time to sell, so they come forward."

But half of the people who came to the office in Melbourne were Westerners, Gibson says. Some had family members who had travelled the world, buying from auctions. Others were downsizing and some from Britain had inherited from a family member with a military background.

Malaysian-born Chong, who studied in Britain, says he entered the field because of his passion for it: "For an Asian to pursue the arts is very different. A lot of parents want their children to be doctors or architects."

He says Chinese art and its valuation are "very delicate and very deep" topics. "You require a specialisation in the field, and we need to identify the fakes. In China a lot of people are making fakes that are very convincing, so we are providing this service to the public. We want to educate people and make sure they don't make rash decisions, because there are a lot of new buyers."

Chong says the ratio of genuine items to fakes is about one to 1,000, "so there are quite a lot out there. For many families who left mainland China and Hong Kong, their great grandparents bought a lot from so-called antiques dealers who were just trying to make a quick buck," says Chong. "It's disheartening. You see someone who is 30 years old with a vase that was their grandfather's, but you have to tell them that it's just a reproduction."

This article appeared in the South China Morning Post print edition as DownUnder